Sheathing ships



UNITED sTaTEs TATEET oEErcE JOHN REVERE, OF BOSTON, MASSACHUSETTS.

SHEATI-IING SHIPS, &c.

Specification of Letters Patent No. 29,916, dated September 4, 1860.

T o all whom it may concern:

Be it known that I, JOHN REVERE, of Boston, in the county of Suolk and State of Massachusetts, have invented a new and useful Improvement in Sheathing Na'vigable Vessels; and I do hereby declare the same to be fully described and represented in the following specication and the accompanying drawings, of which- Figure l, exhibits an external surface view of a series of copper or metallic sheets as applied to a wooden surface or part of the bottom of a ship and in accordance with my invention. Figs. 2, and 3, are longitudinal and transverse sections of the same.

The nature of my invention consists in the direct application to the inner surface of the metallic sheathing and between the same and the bottom or outside planking of a ship or other navigable vessel (Whether such sheathing be zinc, copper, or any composition of metals liable to oxidation by acids or contact with sea water), and so as to be absolutely attached to the sheathing of an insulating coating of such nature, as not only to be capable of resisting the attack of an acid, but of electrically insulating the metallic sheathing from the wood or bottom of the vessel.

My invention further consists, not only in such an application of an insulating medium but in the extension of such between the lapped portions of contiguous sheets of the metallic sheathing, so as to insulate each sheet from that or either of those which may either lap on it or be overlapped by it.

The particular objects of my invention are, rst, complete or nearly thorough protection of the whole sheathing from electrical or galvanic action tending to promote its oxidation; second, a limitation of the electrical or galvanic action of each sheet of sheathing to such sheet, and, third, complete or nearly thorough protection of the metallic sheathing from the action of the natural acid or acids and moisture of the wood of the vessels bottom or from the deteriorating or destructive influence of metallic ballast or cargo.

My invention, if it does not always eifectually prevent the oxidation of the metallic sheathing, by causes as stated, greatly retards the same, and enables a vessels sheathing to last a much longer period than it will under the modes heretofore practiced for applying it.

It is well recognized or understood, that galvanic action is the principal cause of destruction of the copper or metallic sheathing of ships, and is likely to operate more intensely whenever' any irregularity of the composition or character of the sheets may exist, the moisture of the planking of the ship or of the felting usually placed between the sheathing and the planking serving as a conductor of electricity from one sheet of metal to another.

One material or composition I find well adapted to carrying out my invention is asphaltum in so-lution with essential oil of turpentine or combined with coal tar. There are also solutions of various resins or of caoutchouc or gutta percha which from their elasticity permit the necessary bending of the sheet of metal without being either cracked thereby or of having their adhesiveness to the surface impaired.

The insulating material or composition as the case may be, is to be spread on one side of each sheet of the sheathing so as to cover its surface or that part of it which it may be desirable to protect in manner as described, the material or composition by its inherent cementing property connecting or fastening itself firmly to the surface of the sheet. It may also be applied to the thin edges of the sheet if desirable. As the sheets are lapped one on the other when put on the vessels bottom the insulating material should extend between the laps so as to entirely insulate each sheet from those surrounding or next to it.

In the drawings, a, a, a, denote the sheets the metallic sheathing and, b, the wooden bottom or surface on which they are fasw tened, they being secured in place by nails, c, c, c, driven through them and into the wood. These nails may also be covered with the insulating composition or material before being driven.

The layer of the insulating material or medium as applied to each sheet is exhibited in Figs. 2, and 3, at c, by a black line, it being made to pass between the metal sheets i Y. I Il".

Where they lap over one another, such sheets 2. In combination With such an applicabeing` exhibited in red While the Wooden tion of such an insulating composition eX- bottom is drawn in a different color. tending it between the laps of the metallic I claimsheets of sheathing, as and Jfor the purpose 5 l. rIhe application to the inner surface of explained.

metallic sheathing of a ship or other Vessel JN0 REVERE and with respect to the bottom of the vessel as described and for the purpose set Jforth, Witnesses:

of an insulating material or composition of R. H. EDDY, 10 the character specified. F. R. HALE. 

